Beginner

485. JOIN on Multiple Conditions

Learn how to use multiple conditions inside a JOIN to control which records match.

📘 Lesson 485 of 728 ⏱ 12 min 🎯 Intermediate

A JOIN condition can contain multiple expressions connected with AND or other logical operators to create more specific matching rules.

Multiple conditions can make relationships more precise and prevent unrelated records from being joined.

Match employees to assignments using both EmployeeID and AssignmentDate.

SQL 
SELECT
    e.EmployeeName,
    a.AssignmentID
FROM Employees e
INNER JOIN Assignments a
    ON e.EmployeeID = a.EmployeeID
   AND e.DepartmentID = a.DepartmentID;

Used in employee systems, financial transactions, inventory matching, historical data, and effective-date reporting.

  • JOIN conditions can contain multiple expressions.
  • AND requires all conditions to match.
  • Additional conditions can make matching more precise.
  • Multiple conditions can reduce unwanted matches.
  • Always validate the business relationship represented by the conditions.
Can a JOIN have multiple conditions?

Yes. Multiple conditions can be combined in the ON clause.

What does AND do in a JOIN condition?

AND requires all specified conditions to be true for the rows to match.

Have you finished this lesson?

Introduction to SQL – All Lessons